#!/usr/bin/env node
const user ={
  name:'lzj',
    age:20,
  qq:'123'
};
const log=console.log;
log('name:%s',user.name);
log('age:%d',user.age);
log('JSON:%j',user);
log('qq:%s',user.qq);//占位符输出
log('qq:'+user.qq);//拼接字符串输出
console.error('Error!something wrong!');
